What This PR adds a series of 2-6 bit quantization methods, along with quantization mixes, as proposed in #1240 and #1256. Scalar, AVX2, ARM_NEON, and CUDA implementations are provided. Why This is...

Introducing GPT-4.1 in the API—a new family of models with across-the-board improvements, including major gains in coding, instruction following, and long-context understanding. We’re also releasing o...